Autonomous system
AS9618 TCN catv-tokushima
Residential APNIC
Summary
Cable Television Tokushima (TCN)
isp residential legacy
AS9618 (TCN) is held by Cable Television Tokushima (ケーブルテレビ徳島株式会社), known on air as Television Tokushima. It is the largest cable operator in Tokushima Prefecture on Shikoku, and has been a subsidiary of Shikoku Electric Power since 2006. The registry handle catv-tokushima says exactly what it is.
What it's used for
A small regional cable ISP. The AS announces just two IPv4 prefixes, 203.110.96.0/19 and 211.19.160.0/19, for 16,384 addresses in total, plus one IPv6 /32 (2404:2680::/32). The reverse DNS confirms the role directly: sampled addresses come back as usr203110096005.tcn.ne.jp and usr211019176005.tcn.ne.jp, where the usr prefix and the IP encoded straight into the hostname are the standard way a cable operator names its subscriber pool. One sampled address resolves to login.tcn.ne.jp, an operator-side service host rather than a customer line. The single observed BGP neighbour rules out any transit or peering role: this AS sits behind one upstream and exists to give the operator's own cable subscribers addresses.
Notable
- Two clean /19s and nothing else is unusually tidy for a network of this age. Most regional Japanese cable ISPs of comparable size have accreted a dozen or more scattered blocks.
- IPv6 is deployed as a full /32 despite the tiny IPv4 footprint, so the operator's addressing plan has room far beyond its current subscriber base.
- The operator is not independent: it became a subsidiary of Shikoku Electric Power, the regional electric utility, in 2006. The AS is still registered under the cable brand.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Transit providers
1 upstream, 0 downstream and 2 adjacent networks observed; most-used upstreams first.
| AS | Network | Paths seen |
|---|---|---|
| AS7522 | STNet, Incorporated | 153 |
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-11, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 2 prefixes · 16.38K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| JP | Japan | 3 |
Registry
Allocation record
- Registry
- APNIC
- Handle
AS9618- Registry name
- TCN
- Registered
- 1999-08-05
- Last changed
- 2005-08-29
- Allocation
- allocated
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 3 with no ROA
- ROAs
- 0 authorising AS9618
- ASPA
- no ASPA record
- IRR
- 100% registered · 3 of 3 announcements
- Route objects
- 7 naming AS9618
Reputation
Classification and threat
Residential Fixed-line consumer ISP. Addresses here are homes.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 431 networks and 1,768 prefixes, as published 2026-10-12. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere